Variable-speed gearing



Dec. 12 1939. A. J. LENOX VARIABLE-SPEED GEARING 3 Sheets-Sheet 1 Filed Jan, 28, I939 I ffixllll Inventor Attomy;

3 Sheets-Sheet 2 A. J. LENOX VARIABLE-SPEED GEARING Filed- Jan. 28, 1939 Attorneys HM will I IQ Dec. 12, 1939. LENQX 2,183,460

yAR IABLE-SPEED ,GEARING FiledJan. 28, 1939 3 Sheets-Sheet 3 A ttr "rey' Patented Dec. 12, 1939 i UNiTED STATES mam oFrlcE VARIABLE- SPEED GEAR-IN G Andrew James Lenox, Kingston-upon-Hull, England Application January 28, 1939, Serial No. 253,422 In Great Britain January 29, 1938 a 8 Claims. (01. 74-259) The present invention relates to variable-speed Figure 1 shows diagrammatically a simple form gearing of power transmission apparatus and has of construction of the present invention. for its object the provision of relatively simple Figure 2 is .a longitudinal section through a yet eflicicnt means for enabling the elimination practical form of construction suitable for use of a clutch and the necessity for manual gear on vehicles such as motor-cycles, automobiles or i 5 changing. other road vehicles.

The apparatus of the present invention is' ap- Figure 3 is a section on the line 33 of Fig. 2. plicable to road or rail vehicles, aircraft, ships, Figure 4 is'a section on the line 4 i of Fig. 2. or again to power plants of a stationary character. In the diagrammatic form of construction lo According to the present invention and from shown in Figure l of the drawings a power inone aspect thereof, the inertia effect of a rotary put shaft it, through a differential gear I 3, is flywheel is adapted to brake one of a pair of difadapted to drive a power output shaft I2 which ferentially driven shafts coupled to a power inconstitutes one of a pair of dilferentially driven put shaft through a differential gear, to transmit shafts the other of which is indicated at ll.

power from said input shaft through the difier- In the case of vehicles the shaft l2 may be the 15 n al ear to an outpu propeller Shaft Propeller shaft constituted by or coupled to one Stitllting c up e to e Other shaft of the of a pair of differentially driven shafts (not differentially d ve pair. shown) in the vehicle or in the caseof stationary 011 another spec of t Present invention plant it may constitute the usual power shaft of L0 a power input shaft drives adiiferentia gear a machine or machines (not shown) to be driven.

with which is associated two differentially driven The Shafts H a 12 are driven i t some shafts one of which constitutes or is coupled to direction by t shaft to th pr p l haft f th mechanism, to be The differentially driven shaft II has keyed driven and a means for driving a flywheel thereto a spur wheel M which is in mesh with a about its own axis and the other of which is couspur Wheel, 5 adapted to t t t cage 5 pled to means for driving said flywheel about an b t a ft 51 "a a right angles to the flywheel an s, The power output or differentially driven shaft eonnectien be n provided between Seld drlVing [2 has keyed thereto a spur wheel [8 adapted to means. mesh with a spur wheel IQ of a countershaft 20,

o From a St l ur h p t o the present one end of which like the shafts ll, 12 and I1, Vent o D e S a is Coupled through ii (iiiis mounted in bearings in a housing 9, and the fe'rential gear with a pair of differentially driven other end of which i o ted in a bearing of shafts, one of which constitutes, or is coupled t oage Is, to, the propeller shaft of the device or devices o that end f the oountershaft 29 which to be driven and the other of which is connected jects t t cage Hi ther i keyed a sun wheel to the first through a rota y ca e d fl w H with which a planet wheel or pinion 22 is the n t a e Ct produced y rotation of the adapted to mesh, said planet wheel 22 being carfiy ab an aXiS normal to thatt 0f the ried on an intermediate or lay shaft 23 which, e Operating to y the relative Speeds of during rotation of the cage l6; revolves with the 40 rotation of the differentially driven shafts. age about th xi thereof. The intermediate 40 Where the inve ti s app t driving the or lay shaft 25 carries a bevel wheel 24 which road wheels of a vehicle the propeller shaft conmeshes t a b l h l 25 f flywheel h ft stituted by or coupled to one of the differentially 5 located djametrafly of t cage 5 t flydriven shafts is in turn adapted to drive a dif- Wheel h ft arrying a flywheel 21 adapted to fere tial o which the road Wheels of a pai n rotate about the axis of the shaft 26, i. e., at 45 ODlJeSite Sides a Vehicle are coupledright angles to the axis of rotation of the cage.

Where the invention is applied to stationary In operation, power is t tt from an plant, however, one of the differentially driven engine or other Source f power supply ot shafts referred to above may constitute the usual Shown) to the differentially driven hafts I2,

power shaft of the machine to be driven or the through the difierentia l gearing 3 50 power shaft from which a number of machines At one limit of remtive Speeds of t difreceive their dTiVeferentially driven shafts H and [2 when resist- The nvent o is o par c arly described ance to movement of the shaft !2 obtains, such with reference to the accompanying drawings, in as for example, on starting with a heavy load, which the shaft I2 is substantially stationary and the :5

shaft II is driven. As a result of this the cage I5 is rotated through the spur wheels I4, I5, while the spur wheels I8, I9, and the sun wheel 2i remain stationary. It follows that on rotation of the cage with the sun wheel 2I stationary, the planet wheel 22 planetates about the sun wheel 2I causing rotation of the intermediate shaft 23 and the bevel wheels 24, 25, to rotate the flywheel shaft 26 and the flywheel 21.

As the torque on the shaft IIl increases so does the angular rotation of the flywheel 21 about its own axis increase until the inertia effect exerted by the flywheel, in rotating about an axis at right angles to the axis of rotation of the cage, tends to retard said cage rotation. This in turn creates a resistance to rotation of the shaft II and permits of the application of power supply to the shaft I2.

At the other limit of relative speeds of the differentially driven shafts II, I2, the drive is from the shaft IB through the differential gear direct to the shaft I2, the shaft II, spur wheel I I, I5, and cage I6 remaining stationary.

During rotation of the shaft I2 the countershaft 26 also rotates by virtue of the fact that the spur wheel I8 meshes with the spur wheel I9 and rotation of the shaft 20 causes rotation of the sun wheel 2I to effect rotation of the planet wheel 22 about the axis of the shaft 23, whereby the flywheel 2'! is also rotated. Rotation of the flywheel in turn has an inertia eflect tending to maintain the cage in its stationary condition.

During rotation of the shaft I2 and in the event of resistance to rotation thereof being increased, it follows that the speed of the shaft I2 tends to decrease as do also the speeds of the shaft 26 and the flywheel 21 thereby offering a smaller resistance to rotation of the cage I6 and corresponding smaller resistance to rotation of the shaft I I. In other words, the relative increase and decrease of speeds of the differentially driven shafts II and I2 is in inverse ratio.

It will thus be seen that the speeds of the two differentially driven shafts II and I2 are automatically varied in accordance firstly with the speed of rotation of the shaft II) which varies in accordance with the power supply such as for example, in the case of road vehicles on operation of the throttle, and secondly with the load or resistance to movement of the shaft I2, no adjustment of the variable-speed gearing of the power transmission apparatus being required.

Again it will be appreciated that the only factor which can vary the speed of rotation of the flywheel about its own axis is the speed of the shaft ID, i. e., with constant speed of rotation of the shaft III, the speed of rotation of the flywheel 21 remains constant or substantially so, independently of the actual proportion of power output transmitted to the shaft I2 which of course depends on the resistance to movement of said shaft i2. In other words as resistance to rotation of the shaft I2 decreases, so does its speed increase, with the result that the flywheels rotary speed is maintained by virtue of the train of gears IS, IS, 2I, 24 and 25 whilst as rotation imparted to the flywheel 21 by virtue of the rotation of the cage I6 decreases, the rotation imparted to the flywheel by the above train of gears increases, and in consequence the braking effect of the flywheel is maintained.

In the operation of the mechanism it will be appreciated also that the engine or other source of power supply for the shaft I0 is permitted to develop considerable brake horsepower before taking up the load on the shaft I2.

The construction according to Figures 2-4 differs primarily from the diagrammatic form of construction shown in Figure 1 in that the shafts I0, II and I2 are disposed in parallel relationship, whereas in the diagrammatic arrangement according to Figure 1 the shaft I8 is at right angles to the shafts II and I2. In Figures 2-4 the shaft If! has keyed thereto a spur wheel 28 which meshes with a toothed wheel 29 of the differential gear I3, one wheel of which rotates with the differentially driven shaft II and the wheel opposite thereto rotates with a differential shaft 38 to which is keyed a spur wheel 3I in mesh with a spur wheel 32 keyed to the differential and power output shaft I2.

The wheels 28, 29 and the differential I3 are located within the housing 9 whilst that part of the power output or propeller shaft I2 which projects through the end wall of the housing 9 has keyed thereto a spur wheel 33 in mesh with a spur wheel 34 on the countershaft 2D.

The countershaft 20 is splined at 35 to receive a casing 36 which houses the cage I6 of the flywheel 2l, the left hand end of the cage I6 engaging with the differential shaft II at a splined part of the latter.

As in the construction according to Figure l the flywheel 21 is keyed to the flywheel shaft 26 which is at right angles to the cage IE, but in this construction the flywheel shaft projects through the ends of the cage I6 where it carries a bevel wheel 25 adapted to mesh with a bevel wheel or track 3! consisting of an annulus rigid with the inner periphery of the casing 36. In this construction, one limit of relative speeds of the differential shaft II on the one hand and the associated differential shafts 3B and I2 on the other hand is when the drive from the power input shaft I0 is transmitted through the wheels 28, 29, the differential I3, the differential shaft II, the cage I6, the bevel wheels 25, 3l' the casing 36, the countershaft 28 and the spur wheels 34, 33,

to the power output shaft I2. The other limit of relative speeds occurs when the power is transmitted from the input shaft Ill through the spur wheels 28, 29, the differential I3, the differential shaft 38 and the spur wheels 3|, 32 to the power output shaft I2. As in the construction according to Figure l the inertia effect created by rotation of the flywheel 21 about its own axis applies braking load on the cage IE to vary the transmission through the shafts I I and I2 and with increase of speed of the flywheel the greater is the braking load and the smaller is the amount of power transmitted through the shaft I I and cage I6 to the countershaft 29, the spur wheels 34, 33 and the shaft I2, and the greater is the power transmitted through the shaft 30 and the spur wheels 3!, 32 to the shaft I2.

If desired, means may be provided for varying the radius of gyration or effective mass of the flywheel 21', such as for example, by displaceable mass elements on the flywheel.

Again if desired power for rotating the flywheel may be obtained from an electric motor or other source independently of the source of power supply for the shaft I9 thereby permitting variation of the speed of rotation of the flywheel when desired.

I declare that what I claim is:

1. Power transmission apparatus comprising a power input shaft, a differential gear including a wheel rotatable with said input shaft, a pair of differentially driven shafts driven by opposite wheels of said differential gear, a flywheel rotatable about its own axis and about an axis at right angles thereto, means connected with one of said differentially driven shafts for driving the flywheel about one of said axes, means connected to the other of said differentially driven shafts for driving the flywheel about the other of said axes,

and a gear connection between said means con- I nected to the shafts.

2. Power transmission apparatus comprising a power input shaft, a differential gear including a toothed wheel rotatable with said input shaft, a pair of differentially driven shafts driven by said gear, one of which shafts constitutes the propeller shaft of the mechanism to be driven, a flywheel, means connected to said propeller shaft for rotating said flywheel about its own axis, means connected to the other differentially driven shaft for rotating said flywheel about an axis at right angles to the flywheel axis, and planetary gearing between said flywheel rotating means enabling said flywheel on rotation about its own axis to have its rotation about an axis at right angles thereto varied in accordance with the load on said propeller shaft.

3. Power transmission apparatus comprising a rotary cage, a flywheel rotatable about an axis normal to that of the cage, a power input shaft, a differential gear driven by said input shaft, a pair of differentially driven shafts associated with said differential gear and with one of which said cage is rotated at a predetermined gear ratio and a countershaft rotatable at a predetermined gear ratio with said other differential shaft for rotating said flywheel to generate an inertia effect for braking rotating of said cage.

4. Power transmission apparatus comprising a power input shaft, a differential gear including a wheel rotatable with said shaft, a pair of shafts differentially driven by said gear, a countershaft rotatable with one of said differentially driven shafts, a cage rotatable with the other of said differentially driven shafts, a flywheel the axis of which lies normal to that of the cage and planewheel, and forms a bearing for one end of a countershaft, which is adapted to rotate the flywheel and which itself rotates at a predetermined gear ratio with the other differentially driven shaft.

6. Power transmission apparatus as claimed in claim 3 and wherein a planetary gearing is provided between the countershaft and the cage which is coupled for rotation at a predetermined gear ratio with one of the differentially driven shafts, houses the flywheel and forms a bearing for one end of the countershaft which is adapted to rotate the flywheel and which itself rotates at a predetermined gear ratio with the other differentially driven shaft.

7. Power transmission apparatus as claimed in claim 3 and wherein a planetary gearing is provided between the countershaft and the cage and the countershaft carries a spur wheel which drives a pinion on a lay shaft extending longitudinally within and carried by a cage, the said lay shaft having a bevel wheel in mesh with a. bevel Wheel on the flywheel shaft.

'8. Power transmission apparatus as claimed in claim 3 and wherein the cage is directly driven by one of the differentially driven shafts whilst the axis of the flywheel projects through the periphery of the cage and carries a bevel wheel in mesh with a bevel gear on the inner periphery of a casing coaxial with said cage, the said casing rotating in unison with the countershaft.

, YQANDREW JAMES LENOX. 

